Flame retaining gas burner



Aug. 11, 1964 R. w. IMARS ETAL FLAME RETAINING GAS BURNER 2 Sheets-Sheet1 Filed Oct. 21. 1957 INVENTORS ROBERT w. IMARS BY WILL/AM L.R1EHL 6HTTORNEY Au 11, 1964 R.W. [MARS ETAL 3,144,076

FLAME RETAINING GAS BURNER Filed Oct. 21, 1957 2 Sheets-Sheet 2INVENTORS ROBERT M MARS BY WILL/AM L. RIEHL ATTOR E V United StatesPatent 3,144,076 FLAME RETAINING GAS BURNER Robert W. Imars, NewHartford, and William L. Riehl,

Utica, N.Y., assignors to International Heater Company, Utica, N.Y., acorporation of New York Filed Oct. 21, 1957, Ser. No. 691,393 4 Claims.(Cl. 158-413) This invention relates to burners, and more particularlyto gas burners of the type normally employed in heating furnaces forbuildings. The invention also relates to an improved method of retentionof the flame at the burner head or tip.

Atmospheric burners previously presented have produced a flame which wasnot well adapted to be controlled as to size and shape. Such burnerswere therefore not Well suited to be used as conversion burners in afurnace designed for the forced draft or power type oil burners.Combustion zones for the oil burner are usually compact. Accordingly, acompact, controlled flame is desirable in order to achieve maximumheating and flame efficiency therefrom.

Atmospheric burners heretofore presented have had another undesirablecondition in that static pressures building up within the burner tubecause a noisy concussion or flash-back during extinguishment of theflame.

Furthermore, due to the velocity of the fuel-air mixture issuing fromthe burner head, the velocity of flame propagation is likely to beexceeded by this mixture velocity, thus causing blow-off of the flame,and subsequent extinguishment thereof. This causes a dangerous conditionin that the air around the furnace can become both poisonous and highlyexplosive. Attempts have been made to correct this condition by theprovision of two velocities at the burner head, thus to provide amixture of fuel-air issuing from the head and surrounding the mainstream at a reduced velocity. However, the size and shape of the flamecould not be controlled to any great extent with this method.

It is therefore a primary object of this invention to provide a burnerwhich accomplishes combustion of gas within a more limited cubic zonethan was heretofore possible with an atmospheric burner.

It is a further object of this invention to force fuel and combustionair into close association in the combustion zone using atmosphericcombustion and without employing power means of any kind to this end.

Another important object of this invention is to provide a method ofretention of the flame at the burner head by providing a plurality ofvelocities of fuel-air mixture at the burner head and controlling thesecondary air as it enters the combustion zone.

A further object is the provision of means for achieving maximumturbulence of the flame and rapid completion of combustion in order toachieve maximum efliciency of the burner.

In accordance with the present invention, a burner for gaseous fuel isprovided utilizing atmospheric combustion and not aided in any manner bymechanical or electrical or other power means for the achievement ofcombustion at the burner head. The burner head is designed to providethree velocities of fuel and primary air mixture, while means isprovided in the manner of a conduit for supplying secondary air undercontrol to the plished.

A more complete understanding of the present invention may be had bymeans of the following detailed de-' scription taken with reference tothe accompanying drawings in which:

FIGURE 1 is a top plan view of the burner, partly in section.

FIGURE 2 is a side elevation of the burner, partly in section.

FIGURE 3 is a diagrammatic side view of a burner installation, showingthe resultant flame pattern.

FIGURE 4 is a diagrammatic side view of another burner installation,showing the resultant flame pattern.

FIGURE 5 is a cross sectional elevation of the burner head, in part,taken on line 5-5 of FIGURE 6.

FIGURE 6 is an end view of a burner head taken on line 6 of FIGURE 5.

Like reference numerals refer to like parts throughout the severalviews, which illustrate a preferred embodiment of the present invention.The embodiment illustrated is particularly well adapted for use as a gasconversion burner for replacement of oil fired burners. Typical of theoil burners being replaced is the so-called guntype burner, where anelongated burner tube is extended through the furnace wall and the flameis forced into a small cubic area, which is sometimes long and narrow.

With reference to FIGURES 1 and 2, there is illustrated a gas burnerhaving an outer cover 11 of substantially cylindrical shape and having aknob 12 on the closed end thereof for facilitating removal of the cover11. The cover Ill is fastened to the chassis of the burner by means ofsuitable screws 17. The chassis comprises a chassis ring 14 and achassis plate 13 fastened together, and all formed of sheet metal or thelike. An elongated, substantially cylindrical tubular member forming thesecondary air conduit or tube 21 is fastened into the central opening 23in the chassis plate 13.

This assembly is adapted to be mounted at varying height on suitablesupporting legs 18. In this manner, the burner assembly is adapted to beplaced at the correct height in front of the opening in the furnacethrough which an oil burner had been previously installed. The device isalso adapted to be mounted by means of an oil burner mounting flangecapable of adjustment to the size of the secondary air tube 21 outsidediameter.

In the embodiment illustrated, two burner tubes 31 are disposed on asuitable burner drawer plate 22 which is fastened as by welding at itsback end to the manifold 46. Angle brackets 16 are welded to the sidesof the plate 22 and are secured by means of screws 15 to the chassisplate 13. This serves to rigidly maintain the burner tubes in positionwithin the secondary air tube 21. Safety pilot burner 48 is alsofastened to the plate 22, as are the burner tubes 31. The rear end ofthe burner tubes have disposed therein an adjustable mixer tube. Thismixer tube 34 is mounted slidable inwardly and outwardly in the end ofthe burner tube 31, and is adapted to be locked in any position by meansof a suitable lock screw 35. By adjusting the position of the mixer tube34, the amount of air entering the burner tube 31 may be controlled. Themixer tube 34 has a flared end for the more eflicient mixing of fuel gasand air.

With reference to FIGURES 5 and 6, the burner head 34) is described ascomprising the burner tube 31 having an inner sleeve 33 of reduceddiameter placed concentrically therein. A corrugated type ribbon sleeve32 is disposed between the inner sleeve 33 and the burner tube 31. Theinner sleeve 33 is positioned at the outer end of the burner head 3%,and is longitudinally shorter than the ribbon sleeve 32.

It is seen that gas and primary air travel through the burner tube 31 inthe direction of arrows 1, 2 and 3. The principal volume of this mixturepasses through the burner head 35) through the interior of the innersleeve 33, as indicated by the arrows 1. A secondary volume of principalvolume of mixture in opening 1. A third portion of the mixture entersopenings 3 between the corrugated sleeve 32and the burner tube 31, andtravels at a reduced velocity in relation to the velocity of the secondportion.

Combustion air enters the enclosure formed by cover 11 through a spacebetween cover 11 and the adjustable secondary air damper 10, which issupported by means of studs 19 welded to the damper near the forwardedge thereof, and extending through slot 20 formed in chassis ring 14.Any conventional lock nut (not shown) threaded to the studs 19 securesthe damper in any fixed position. When the burner is installed, theinstaller 'makes a suitable air intake adjustment by rotating damper 10inside chassis ring 14 and cover 11, thus varying the size of theopening as required. The damper is then locked in position by means ofthe lock nuts on studs 19. Secondary air enters the secondary air tube21 through opening 23 in the chassis 13, and passes out through theouter end of tube 21, at the same time surrounding the two burner heads30, and providing secondary air to aid in completion of combustion.

It is therefore seen that portion 1 of the gas and primary airconstitutes the principal volume of gas-air mixture issuing at maximumvelocity from the burner tip or head 30. This first portion is pilotedby a proportionately slower second portion issuing from openings 2 atthe'burner head at reduced velocity proportionately to the velocity ofthe first portion. This second portion is likewise piloted by a thirdportion issuing from openings 3 at the burner head 30 at a reducedvelocity proportionately to the velocity of the second portion. Thecombustion is sustained by the secondary air entering the combustionzone through the tube 21. By this novel apparatus an improved method ispresented for the retention of the flame at the burner head.

A flame spreader 24 comprises a plate of heat resistant metal or thelike which is specially shaped to deflect the flame so as to form theflame into the substantial shape of a ball or globe. The flame spreaderplate 24 is maintained in position in front of the burner heads 30 bymeans of a suitable rod 25, which is fastened at its other end to thesecondary air tube 21. The flame spreader 24 in the present embodimentis substantially as wide as the width of the two burner heads 30. Aportion of the flame is divided, FIGURE 5, and the remainder of theflame travels around the spreader 24 in a substantially sphericalmanner, being piloted by the two reduced velocities of the second andthird portions of fuel-air mixture, and the secondary air.

In the operation of the burner, reference is made to FIGURES 3 and 4.The burner is mounted, either by means of the supporting legs 18, or bythe oil burner mounting flange 9 in front of a conventional furnace,with the secondary air tube 21 projecting into the combustion zone, theburner heads 30 being inside the tube 21, as hereinbefore described.This is diagrammatically illustrated in FIGURES 3 and 4. FIGURE 3illustrates operation of the burner using the flame spreader 24. Thefurnace 6 having refractory brick 7 disposed therein in the conventionalmanner, it is to be understood that minimum distances between the wallsof the combustion zone and the burner head are observed in accordancewith standards maintained by those skilled in the art.

The thermostat (not shown) is connected in the conventional manner tothe control valve 43, and the control valve 43 is connected to the gassupply by means of inlet pipe 41, and is connected to the pilot burner48 by means of gas line 49. Pressure regulating valve 42 is placed inthe gas line 41 between the source of gas and the control valve 43. Thisvalve 42 regulates the pressure of the gas flow, maintaining an even andconstant pressure at all times. As is well known to those skilled in theart, this practice will cause better and more eflicient operation of theburner.

When the thermostat (not shown) indicates the need for heat, theautomatic control valve 43 supplies gas to the manifold 46 by means ofthe valve 43. This gas issues through the orifices 47 from the manifold46 to the mixer tubes 34, through the burner tubes 31 to the burnerheads 30, where the fuel-air mixture is ignited by the pilot flame.Primary air enters the mixer tubes 34 along with the gas from orifices47 and mixes with In order to produce a flame at the burner head 30which most efliciently and economically utilizes the gas fuel, the mixertubes 34 are adjusted so that the head space 36, FIGURE 4, is of theproper size to permit the proper amount of primary air to enter throughthis head space 36 into the tubes 31. When the mixer tubes 34 areproperly adjusted, they are locked in place by means of the lock screw35. To accomplish this, the outer cover 11 is removed by loosening orremoving screw 17 and pulling the cover backwardly by the handle knob12. This procedure is reversed to replace the outer cover 11 inposition.

Should at any time the pilot burner 48 become clogged or otherwiseinoperable, or should the burner unit require any kind of service, theentire assembly may be removed from the chassis plate 13, ring 14, andsecondary air tube 21 quickly and easily, even while the burner is hot.The outer cover is removed as before, and the screws 15 are removed,loosening the entire burner unit from the rest of the assembly. If rigidgas inlet lines have been used, it will become obvious that the linewill have to be disconnected also. The entire burner unit may then beremoved from the back end of the chassis plate, as illustrated in FIGURE2.

An opening, not shown, in the outer cover 11 is provided for theadmittance of air into the interior thereof. This air enters the mixertubes 31 as primary air, and the tube 21 as secondary air for theburner. The opening is adjustable to regulate the amount of air enteringthe tubes for the purpose of providing more eflicient burning of thefuel, and may be locked open or shut in any desired position by means ofa conventional lock screw.

FIGURE 6 illustrates the use of the burner without the flame spreader24, the refractory brick 7 being used to deflect the flame 8 in the bestway to provide efiicient heating. As in the case where the burner isused as a conversion unit from oil to gas, it is well known that oilburner combustion zones are sometimes long and narrow. Therefore, theflame spreader may or may not be used according to the dimensions of theparticular combustion zone. In a small combustion area, it is desirableto have minimum flame height, therefore making it desirable to use theflame spreader.

It is seen that the burner heads are substantially the same diameter asthe burner tubes. This condition serves to eliminate the building up ofstatic pressures within the tubes, thus eliminating noisy concussionwhen the flame is extinguished.

It is therefore seen that the leading objects of this invention are bestaccomplished by the method of placing an inner sleeve of reduceddiameter concentrically in the end of the burner head and inserting acorrugated sleeve between the inner sleeve and the burner tube. Bymaking the inner sleeve longitudinally shorter than the corrugatedsleeve, a series of ports are formed between the corrugated sleeve andthe burner tube which are longitudinally longer than the series of portsbetween the inner sleeve and the corrugated sleeve. Thus, fuel mixtureis issued in its principal volume at maximum velocity through the innersleeve, at an intermediate velocity through the shorter ports betweenthe inner sleeve and the corrugated sleeve, and at a low velocitybetween the corrugated sleeve and the burner tube. As hereinbeforedescribed, the principal volume of gas is held piloted by theintermediate velocity portion, and the intermediate velocity portion isheld piloted by the low velocity portion.

In summary, some of the advantages of the present invention may beenumerated as follows: (1) All combustion air is conducted by the blasttube to the exact point of use. The air immediately mixes intimatelywith the fire. In searching for the fire it does not sweep over and coolsome of heating surface nor get loose above the fire to dilute the fluegases. This provides maximum efiiciency in a minimum of space. (2) Thecombination of high velocity burners and the flame spreader produces aconcentrated well aerated ball of fire. Lower velocity with animproperly shaped or located spreader would result in a distorted flamepattern. The present invention produces deep down heat transfer wellcentered in the combustion chamber.

(3) Each of the burner develops a three stage discharge velocity, theinner velocity being highest, and encompassed by an intermediatevelocity, and then surrounded by a lower velocity. This provides quietoperation, exceptional pilot stability and excellent aeration.

A particular embodiment of the invention having been described for thepurpose of illustration only, it is to be understood that the inventionis not to be limited thereto, but is to be construed as fairly fallswithin the spirit and scope of the appended claims.

We claim:

1. In a burner for gaseous fuel, a pilot burner for igniting said fuel,a burner tube receiving gaseous fuel from an orifice through a mixertube mounted slidable inwardly and outwardly therein for regulating theprimary air entering therein, and a burner head having an inner sleeveof reduced diameter with respect to said tube placed concentricallytherein and a corrugated ribbon sleeve disposed between said innersleeve and said burner tube, said sleeves being positioned at the outerend of said burner head, said inner sleeve being longitudinally shorterthan said corrugated sleeve; said burner tube maintained rigidly inposition in a secondary air conduit, said inner sleeve in said burnertube defining a first opening therethrough for the issuance of the principal volume of a fuel mixture, second openings being defined betweensaid inner sleeve and said corrugated sleeve for the issuance of saidfuel mixture at a reduced velocity with respect to the velocity of saidprincipal volume of said mixture, third openings being defined betweensaid corrugated sleeve and said burner tube for the issuance of saidfuel mixture at a reduced velocity with respect to the velocity of saidmixture issuing through said second openings, said fuel mixture issuingfrom said first opening being piloted by said mixture issuing at areduced velocity from said second openings, and said mixture issuingfrom said second openings being piloted by said mixture issuing at afurther reduced velocity from said third openings; said mixture beingignited by said pilot burner and the resultant flame being supported bysecondary air traveling through the secondary air conduit.

2. In a burner for gaseous fuel according to claim 1, a shaped platemaintained in position in front of said burner head for deflecting saidflame, whereby maximum turbulence of said flame and rapid completion ofcombustion is achieved.

3. A burner head for a burner for gaseous fuel, said burner headcomprising a burner tube for receiving said gaseous fuel and mixing saidfuel with primary air therein, an inner sleeve of reduced diametermounted con centrically in one end of said burner tube, a corrugatedsleeve mounted between said inner sleeve and said end of said burnertube, said inner sleeve being longitudinally shorter than saidcorrugated sleeve; said inner sleeve forming a first openingtherethrough for passing the principal volume of said fuel at maximumvelocity, a first series of ports being formed between said inner sleeveand said corrugated sleeve for passing a portion of said fuel at anintermediate velocity, and a second series of ports being formed betweensaid corrugated sleeve and said burner tube for passing a portion ofsaid fuel at low velocity therethrough.

4. In a burner tube for a burner for gaseous fuel, means forming aburner head for said burner tube, said means providing three velocitiesof said fuel issuing from said burner head, said means comprising aninner sleeve of reduced diameter placed concentrically in one end ofsaid burner tube, a corrugated sleeve placed between said inner sleeveand said burner tube in the end thereof; said corrugated sleeve forminga first series of ports between said inner sleeve and said corrugatedsleeve, and a second series of ports between said corrugated sleeve andsaid burner tube; said inner sleeve being longitudinally shorter thansaid corrugated sleeve, said second series of ports being longitudinallygreater than said first series, said inner sleeve forming an openingtherethrough; whereby said fuel is issued from said opening at maximumvelocity and through said first series of ports at intermediate velocityand through said second series of ports at low velocity.

References Cited in the file of": this patent UNITED STATES PATENTS745,872 Machlet Dec. 1, 1903 1,242,992 Sheridan Oct. 16, 1917 1,411,063Needham Mar. 28, 1922 1,644,610 Reichhelm Oct. 4, 1927 2,121,948 BorlandJune 28, 1938 2,467,626 Norman Apr. 19, 1949 2,540,308 Weyenberg et a1.Feb. 6, 1951 2,649,777 Saper-sztejn Aug. 25, 1953 2,658,569 Hughes eta1. Nov. 10, 1953 2,858,729 Keyes Nov. 4, 1958 FOREIGN PATENTS 515,433France Nov. 26, 1920 Add. 23,291 France May 21, 1921

1. IN A BURNER FOR GASEOUS FUEL, A PILOT BURNER FOR IGNITING SAID FUEL,A BURNER TUBE RECEIVING GASEOUS FUEL FROM AN ORIFICE THROUGH A MIXERTUBE MOUNTED SLIDABLE INWARDLY AND OUTWARDLY THEREIN FOR REGULATING THEPRIMARY AIR ENTERING THEREIN, AND A BURNER HEAD HAVING AN INNER SLEEVEOF REDUCED DIAMETER WITH RESPECT TO SAID TUBE PLACED CONCENTRICALLYTHEREIN AND A CORRUGATED RIBBON SLEEVE DISPOSED BETWEEN SAID INNERSLEEVE AND SAID BURNER TUBE, SAID SLEEVES BEING POSITIONED AT THE OUTEREND OF SAID BURNER HEAD, SAID INNER SLEEVE BEING LONGITUDINALLY SHORTERTHAN SAID CORRUGATED SLEEVE; SAID BURNER TUBE MAINTAINED RIGIDLY INPOSITION IN A SECONDARY AIR CONDUIT, SAID INNER SLEEVE IN SAID BURNERTUBE DEFINING A FIRST OPENING THERETHROUGH FOR THE ISSUANCE OF THEPRINCIPAL VOLUME OF A FUEL MIXTURE, SECOND OPENINGS BEING DEFINEDBETWEEN SAID INNER SLEEVE AND SAID CORRUGATED SLEEVE FOR THE ISSUANCE OFSAID FUEL MIXTURE AT A REDUCED VELOCITY WITH RESPECT TO THE VELOCITY OFSAID PRINCIPAL VOLUME OF SAID MIXTURE, THIRD OPENINGS BEING DEFINEDBETWEEN SAID CORRUGATED SLEEVE AND SAID BURNER TUBE FOR THE ISSUANCE OFSAID FUEL MIXTURE AT A REDUCED VELOCITY WITH RESPECT TO THE VELOCITY OFSAID MIXTURE ISSUING THROUGH SAID SECOND OPENINGS, SAID FUEL MIXTUREISSUING FROM SAID FIRST OPENING BEING PILOTED BY SAID MIXTURE ISSUING ATA REDUCED VELOCITY FROM SAID SECOND OPENINGS, AND SAID MIXTURE ISSUINGFROM SAID SECOND OPENINGS BEING PILOTED BY SAID MIXTURE ISSUING AT AFURTHER REDUCED VELOCITY FROM SAID THIRD OPENINGS; SAID MIXTURE BEINGIGNITED BY SAID PILOT BURNER AND THE RESULTANT FLAME BEING SUPPORTED BYSECONDARY AIR TRAVELING THROUGH THE SECONDARY AIR CONDUIT.